In recent years, suggested are various obstacle detecting devices which detect an obstacle in front of the own vehicle using imaging devices such as a camera mounted on an own vehicle and a millimeter wave radar to predict a collision of a vehicle. Moreover, suggested is a technique of obtaining information of a detected object such as a vehicle, for example, which may be located in a dead angle area of the own vehicle (referred to as “the dead angle-detected object” hereinafter) by receiving information, which is detected by the obstacle detecting device, from other vehicle using a vehicle-to-vehicle communication system.
A device described in Patent Document 1, for example, estimates a path of the own vehicle based on a position of the own vehicle, a speed vector of the own vehicle, or an operation of a direction indicator, for example, determines a collision risk between the own vehicle and the dead angle-detected object based on the path of the own vehicle and the information of the dead angle-detected object, and notifies a driver of the own vehicle of a warning or a collision-avoidance operation of the own vehicle when it is determined that there is a high collision risk.